1 files changed, 186 insertions, 11 deletions

diff --git a/lib/ubsan.c b/lib/ubsan.c
index 60c7099857a0..456e3dd8f4ea 100644
--- a/lib/ubsan.c
+++ b/lib/ubsan.c
@@ -14,10 +14,92 @@
 #include <linux/types.h>
 #include <linux/sched.h>
 #include <linux/uaccess.h>
+#include <linux/ubsan.h>
 #include <kunit/test-bug.h>
 
 #include "ubsan.h"
 
+#if defined(CONFIG_UBSAN_TRAP) || defined(CONFIG_UBSAN_KVM_EL2)
+/*
+ * Only include matches for UBSAN checks that are actually compiled in.
+ * The mappings of struct SanitizerKind (the -fsanitize=xxx args) to
+ * enum SanitizerHandler (the traps) in Clang is in clang/lib/CodeGen/.
+ */
+const char *report_ubsan_failure(u32 check_type)
+{
+	switch (check_type) {
+#ifdef CONFIG_UBSAN_BOUNDS
+	/*
+	 * SanitizerKind::ArrayBounds and SanitizerKind::LocalBounds
+	 * emit SanitizerHandler::OutOfBounds.
+	 */
+	case ubsan_out_of_bounds:
+		return "UBSAN: array index out of bounds";
+#endif
+#ifdef CONFIG_UBSAN_SHIFT
+	/*
+	 * SanitizerKind::ShiftBase and SanitizerKind::ShiftExponent
+	 * emit SanitizerHandler::ShiftOutOfBounds.
+	 */
+	case ubsan_shift_out_of_bounds:
+		return "UBSAN: shift out of bounds";
+#endif
+#if defined(CONFIG_UBSAN_DIV_ZERO) || defined(CONFIG_UBSAN_INTEGER_WRAP)
+	/*
+	 * SanitizerKind::IntegerDivideByZero and
+	 * SanitizerKind::SignedIntegerOverflow emit
+	 * SanitizerHandler::DivremOverflow.
+	 */
+	case ubsan_divrem_overflow:
+		return "UBSAN: divide/remainder overflow";
+#endif
+#ifdef CONFIG_UBSAN_UNREACHABLE
+	/*
+	 * SanitizerKind::Unreachable emits
+	 * SanitizerHandler::BuiltinUnreachable.
+	 */
+	case ubsan_builtin_unreachable:
+		return "UBSAN: unreachable code";
+#endif
+#if defined(CONFIG_UBSAN_BOOL) || defined(CONFIG_UBSAN_ENUM)
+	/*
+	 * SanitizerKind::Bool and SanitizerKind::Enum emit
+	 * SanitizerHandler::LoadInvalidValue.
+	 */
+	case ubsan_load_invalid_value:
+		return "UBSAN: loading invalid value";
+#endif
+#ifdef CONFIG_UBSAN_ALIGNMENT
+	/*
+	 * SanitizerKind::Alignment emits SanitizerHandler::TypeMismatch
+	 * or SanitizerHandler::AlignmentAssumption.
+	 */
+	case ubsan_alignment_assumption:
+		return "UBSAN: alignment assumption";
+	case ubsan_type_mismatch:
+		return "UBSAN: type mismatch";
+#endif
+#ifdef CONFIG_UBSAN_INTEGER_WRAP
+	/*
+	 * SanitizerKind::SignedIntegerOverflow emits
+	 * SanitizerHandler::AddOverflow, SanitizerHandler::SubOverflow,
+	 * or SanitizerHandler::MulOverflow.
+	 */
+	case ubsan_add_overflow:
+		return "UBSAN: integer addition overflow";
+	case ubsan_sub_overflow:
+		return "UBSAN: integer subtraction overflow";
+	case ubsan_mul_overflow:
+		return "UBSAN: integer multiplication overflow";
+#endif
+	default:
+		return "UBSAN: unrecognized failure code";
+	}
+}
+
+#endif
+
+#ifndef CONFIG_UBSAN_TRAP
 static const char * const type_check_kinds[] = {
 	"load of",
 	"store to",
@@ -138,8 +220,8 @@ static void ubsan_prologue(struct source_location *loc, const char *reason)
 {
 	current->in_ubsan++;
 
-	pr_err("========================================"
-		"========================================\n");
+	pr_warn(CUT_HERE);
+
 	pr_err("UBSAN: %s in %s:%d:%d\n", reason, loc->file_name,
 		loc->line & LINE_MASK, loc->column & COLUMN_MASK);
 
@@ -149,29 +231,120 @@ static void ubsan_prologue(struct source_location *loc, const char *reason)
 static void ubsan_epilogue(void)
 {
 	dump_stack();
-	pr_err("========================================"
-		"========================================\n");
+	pr_warn("---[ end trace ]---\n");
 
 	current->in_ubsan--;
 
 	check_panic_on_warn("UBSAN");
 }
 
+static void handle_overflow(struct overflow_data *data, void *lhs,
+			void *rhs, char op)
+{
+
+	struct type_descriptor *type = data->type;
+	char lhs_val_str[VALUE_LENGTH];
+	char rhs_val_str[VALUE_LENGTH];
+
+	if (suppress_report(&data->location))
+		return;
+
+	ubsan_prologue(&data->location, type_is_signed(type) ?
+			"signed-integer-overflow" :
+			"unsigned-integer-overflow");
+
+	val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
+	val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
+	pr_err("%s %c %s cannot be represented in type %s\n",
+		lhs_val_str,
+		op,
+		rhs_val_str,
+		type->type_name);
+
+	ubsan_epilogue();
+}
+
+void __ubsan_handle_add_overflow(void *data,
+				void *lhs, void *rhs)
+{
+
+	handle_overflow(data, lhs, rhs, '+');
+}
+EXPORT_SYMBOL(__ubsan_handle_add_overflow);
+
+void __ubsan_handle_sub_overflow(void *data,
+				void *lhs, void *rhs)
+{
+	handle_overflow(data, lhs, rhs, '-');
+}
+EXPORT_SYMBOL(__ubsan_handle_sub_overflow);
+
+void __ubsan_handle_mul_overflow(void *data,
+				void *lhs, void *rhs)
+{
+	handle_overflow(data, lhs, rhs, '*');
+}
+EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
+
+void __ubsan_handle_negate_overflow(void *_data, void *old_val)
+{
+	struct overflow_data *data = _data;
+	char old_val_str[VALUE_LENGTH];
+
+	if (suppress_report(&data->location))
+		return;
+
+	ubsan_prologue(&data->location, "negation-overflow");
+
+	val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
+
+	pr_err("negation of %s cannot be represented in type %s:\n",
+		old_val_str, data->type->type_name);
+
+	ubsan_epilogue();
+}
+EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
+
+void __ubsan_handle_implicit_conversion(void *_data, void *from_val, void *to_val)
+{
+	struct implicit_conversion_data *data = _data;
+	char from_val_str[VALUE_LENGTH];
+	char to_val_str[VALUE_LENGTH];
+
+	if (suppress_report(&data->location))
+		return;
+
+	val_to_string(from_val_str, sizeof(from_val_str), data->from_type, from_val);
+	val_to_string(to_val_str, sizeof(to_val_str), data->to_type, to_val);
+
+	ubsan_prologue(&data->location, "implicit-conversion");
+
+	pr_err("cannot represent %s value %s during %s %s, truncated to %s\n",
+		data->from_type->type_name,
+		from_val_str,
+		type_check_kinds[data->type_check_kind],
+		data->to_type->type_name,
+		to_val_str);
+
+	ubsan_epilogue();
+}
+EXPORT_SYMBOL(__ubsan_handle_implicit_conversion);
+
 void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs)
 {
 	struct overflow_data *data = _data;
-	char rhs_val_str[VALUE_LENGTH];
+	char lhs_val_str[VALUE_LENGTH];
 
 	if (suppress_report(&data->location))
 		return;
 
 	ubsan_prologue(&data->location, "division-overflow");
 
-	val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
+	val_to_string(lhs_val_str, sizeof(lhs_val_str), data->type, lhs);
 
 	if (type_is_signed(data->type) && get_signed_val(data->type, rhs) == -1)
 		pr_err("division of %s by -1 cannot be represented in type %s\n",
-			rhs_val_str, data->type->type_name);
+			lhs_val_str, data->type->type_name);
 	else
 		pr_err("division by zero\n");
 
@@ -339,9 +512,10 @@ void __ubsan_handle_load_invalid_value(void *_data, void *val)
 {
 	struct invalid_value_data *data = _data;
 	char val_str[VALUE_LENGTH];
+	unsigned long ua_flags = user_access_save();
 
 	if (suppress_report(&data->location))
-		return;
+		goto out;
 
 	ubsan_prologue(&data->location, "invalid-load");
 
@@ -351,14 +525,13 @@ void __ubsan_handle_load_invalid_value(void *_data, void *val)
 		val_str, data->type->type_name);
 
 	ubsan_epilogue();
+out:
+	user_access_restore(ua_flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
 
 void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
 					 unsigned long align,
-					 unsigned long offset);
-void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
-					 unsigned long align,
 					 unsigned long offset)
 {
 	struct alignment_assumption_data *data = _data;
@@ -384,3 +557,5 @@ void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
 	ubsan_epilogue();
 }
 EXPORT_SYMBOL(__ubsan_handle_alignment_assumption);
+
+#endif /* !CONFIG_UBSAN_TRAP */